Hydraulic brake systems are common in the automotive world. The incompressible brake fluid extends from a brake pedal actuated master cylinder to each of the brakes located on the vehicle wheels. The master cylinder and plural slave cylinders are used in conjunction with a fluid containing brake line to distribute the flow of the brake fluid in an appropriate manner to the brakes. In certain situations, brakes can be applied so severely that one or more wheels can lock up.
Although automatic brake systems have been devised which monitor whether one or more wheels have locked up and divert fluid in a rapid fashion away from the locked up brake to ensure maximum braking at times, it is common in vehicles both with and without automatic brake systems (ABS) to induce pressure pulses in the non-compressible brake fluid.
For example, with ABS Systems, severe pressure on the brake pedal can result in a sensation of “chatter” as the valving system diverts brake fluid away from a brake which is being locked. These fluid pulses stress the system. Even in vehicles without ABS, anomalies along the interface between the friction pad and the brake engaging surface can cause fluidic pressure pulses similar to the chatter experienced with ABS.
The following patents reflect the state of the art of which applicants are aware and is included herewith to disclose and discharge applicants' acknowledged duty to disclose relevant prior art. Is respectfully stipulated, however that no single reference anticipates and no combination of references renders obvious the nexus of the instant invention as set forth hereafter.
U.S. PAT. NO.ISSUE DATEINVENTOR912.502Feb. 16, 1909Squires3,064,687Nov. 20, 1962Natho, et al.3,757,825Sep. 11, 1973Givens, et al.3,893,486Jul. 8, 1975Myers4,166,655Sep. 4, 1979Spero4,188,073Feb. 12, 1980Ishikaw, et al.4,220,376Sep. 2, 1980Spero4,301,908Nov. 24, 1981Fukuda, et al.5,078,455Jan. 7, 1992Washington5,085,298Feb. 4, 1992Sollami5,380,074Jan. 10, 1995Jones5,390,898Feb. 21, 1995Kim5,468,056Nov. 21, 1995Kim5,664,848Sep. 9, 1997Muraski5,753,807May 19, 1998Trueman, et al.5,820,227Oct. 13, 1998Spero6,322,160Nov. 27, 2001Loh, et al.6,347,841Feb. 19, 2002Kim
For example, the patents to Spero U.S. Pat. No. 4,220,376 teaches the use of a pressure equalizing devices. In addition, Spero has modified the equalizer in that patent as disclosed in his U.S. Pat. No. 4,166,655. Finally, Spero recognized the limitations in those two patents by developing a further U.S. Pat. No. 5,820,227. Columns 1 and 2 of the '227 patent list some of the frailties in Spero's earlier patents as well as that of the patent to Washington, U.S. Pat. No. 5,078,455.
The remaining patents diverge from the nexus of the instant invention even further.